Thawban reported,
The Prophet ﷺ said, "I know people from my nation who will come on the Day of Resurrection with good deeds like the white mountains of Tihamah, but Allah 
will turn them into scattered dust."Thawban said, "Messenger of Allah, describe them to us, make them clear to us, so that we do not become among them without realizing it."He said, "They are your brothers and from your own kind. They take from the night in worship as you do, but they are people who, when alone with what Allah has forbidden, violate it."
Azami 16218
Hasanعن ثوبان
عن النبي ﷺ أنه قال: لأعلمن أقواما من أمتي يأتون يوم القيامة بحسنات أمثال جبال تهامة بيضا، فيجعلها الله عز وجل هباء منثورا، قال ثوبان: يا رسول الله، صفهم لنا، جلهم لنا أن لا نكون منهم، ونحن لا نعلم، قال: أما إنهم إخوانكم، ومن جلدتكم، ويأخذون من الليل كما تأخذون، ولكنهم أقوام إذا خلوا بمحارم الله انتهكوها.
It was narrated by Ibn Majah (4245), Ruyani in his Musnad (658), and Tabarani in Al-Awsat (4632), all of them from the hadith of Isa bin Yunus Ramli, who said, Uqba bin Alqama bin Hudayj Maafiri narrated to us, from Artah bin Munzir, from Abu Amir Alhani, from Thawban, and he related it.Its chain is hasan because of Isa bin Yunus Ramli and his teacher Uqba bin Alqama bin Hudayj Maafiri, for both of them are hasan al-hadith. Munziri said in Targhib (3575), "Ibn Majah narrated it, and its narrators are trustworthy." Busiri said, "This chain is sahih, and its men are trustworthy. Abu Amir Alhani's name is Abdullah bin Ghabir."His saying, "When they are alone with the forbidden things of Allah they violate them," means they treat them as permissible. Some scholars of knowledge said that this is specific to the hypocrites, based on the words of the Almighty, "They hide from people but do not hide from Allah, and He is with them when they plot by night that which is not pleasing in speech, and Allah is encompassing of what they do" [Nisa 4:108].Others said that it is superseded by the statement of the Prophet ﷺ, "All of my nation will be forgiven except those who openly commit sin, and part of openly committing sin is that a man does a deed at night, then in the morning, after Allah has concealed it for him, he says, 'O so-and-so, I did such and such last night,' when his Lord had concealed it through the night, but in the morning he uncovers Allah's concealment of him." This was narrated by Bukhari and Muslim, and it has already been referenced.